Fix missing parenthesis in documentation

Author: BigStupideer

docs/quickstart/server.mdx

@@ -896,7 +896,7 @@ public class WeatherService {
 
   @Tool(description = "Get weather alerts for a US state")
   public String getAlerts(
-      @ToolParam(description = "Two-letter US state code (e.g. CA, NY)" String state
+      @ToolParam(description = "Two-letter US state code (e.g. CA, NY)") String state
   ) {
       // Returns active alerts including:
       // - Event type